In high temperature processes involving powders and in particular metal powders, it is sometimes desirable to react the powder with a gas. For example, to achieve a low level of oxygen in a metal powder, it is desirable to react the powder with a reducing gas such as hydrogen. Or to produce a desired level of oxygen in the powder, it is desirable to react the powder with oxygen. In high temperature processes, such as in plasma processes, this is difficult to do because the nature of the high temperature equipment is limiting as far as dispersion of the reacting gas.
The present invention provides an apparatus which allows dispersion of the reacting gas in a high temperature process so that reaction of the powder with the gas can be carried out efficiently.